Experiments allow researchers to randomly vary the key manipulation, the instruments of measurement, and the sequences of the measurements and manipulations across participants. To date, however, the advantages of randomized experiments to manipulate both the aspects of interest and the aspects that threaten internal validity have been primarily…

The presence of suppression (and multicollinearity) in multiple regression analysis complicates interpretation of predictor-criterion relationships. The mathematical conditions that produce suppression in regression analysis have received considerable attention in the methodological literature but until now nothing in the way of an analytic…

Based on Activity Theory, this article examines attitude formation in human learning as shaped by the experiences of individual learners with various learning objects in particular learning contexts. It hypothesizes that a learner's object-related perceptions, personality traits and situational perceptions may have different relationships with the…

L. L. Thurstone's (1927) model provides a powerful framework for modeling individual differences in choice behavior. An overview of Thurstonian models for comparative data is provided, including the classical Case V and Case III models as well as more general choice models with unrestricted and factor-analytic covariance structures. A flow chart…

Recent theoretical advances in working memory guided analyses of cognitive measures in 122 children with dyslexia and their 200 affected biological parents in families with a multigenerational history of dyslexia. Both children and adults were most severely impaired, on average, in three working memory components- phonological word-form storage,…